Reflective displays belong to a class of displays called nonemissive displays which do not dominantly rely on an internal light source in order to render an image. Generally speaking, nonemissive displays render images by modulation of an ambient illuminant. More specifically, reflective displays render images by selectively reflecting an ambient illuminant currently incident on the display. Such displays are therefore different from conventional displays such as CRTs or transmissive LCDs, which are emissive, self-luminous displays that dominantly rely on a fixed, internal light source to display the image. Reflective displays are fabricated from a variety of materials and operating mechanisms, including, for example, cholesteric liquid crystal displays and electrophoretic displays.
In order to display colors, reflective displays can use an additive color model, such as a RGB color model, or a subtractive color model, such as a CMY color model. Reflective displays are driven by color primary signals which correspond to the color model being used. For example, if a reflective display uses the subtractive CMY color model, it is driven by a color primary signal corresponding to cyan, a color primary signal corresponding to magenta, and a color primary signal corresponding to yellow.
In recent years, commercial use of reflective displays has gained momentum. As one example, reflective displays have increasingly popular application in electronic paper technologies such as electronic book readers. Electronic book readers display digital books and may allow a user to download and store different documents for viewing. Due to the use of reflective displays, electronic book readers have a paper-like quality which allows a user to comfortably view a displayed document under an ambient illuminant.